Aeroplane propeller



June 13, 1933. s, FTACEK d '1,913,590

AEROPLANE PROPELLER Filed Feb. 24, 1931 STEVEN FTACEK Patented June 13, 1933` STEVEN nfrnonmor orrnwmrnmnors AnnorLnNn rnornnnnn ApplicationilcdFebruary 24, 1931. Serialloiil'YiZ.

i l invention" appertains to vehicle i propulsion, and more particularly to an" improved propellerfor use in conjunction with airhcrafts, such as` aeroplanes,fand the like.

One ofthe primary objects ofmy invention is to -provide an improved aeroplane propeller, so constructed as to eifectively reduce head resistance, and at the `same time obtain` a'niaximum amount of action on the air for 0 drawing theaeroplane through the air.

` Another salient object of my invention 'is to provide an improved propeller which will draw `the aeroplane through the air with a maximum amountof speed with a minimum D amount of engine revolutions, whereby the necessity `of runningfthe engine at a high rate of speed will be eliminated.

` further `important object of my invention is the provisionof an aeroplane propelling device embodying apropel-ler shaft having` connected therewith at spaced points, a plurality of propeller blades, the blades being arrangel atfan angle to one another and w gradually 'diminishing in length toward the front end ofthepropeller shaft.;`

` Alfurther `.object of Amy invention is the provision of a spiral lead head on the forward end of the propeller shaft, the spiral head acting as means for reducing head resistance and at the same time to draw the propeller through thelair and to direct the air on the radial blade of the propeller.

A further object of `my invention is the r provision of novel means for mountingthe` blades on the propeller shaft, whereby the blades can be readily adjusted and readily removed in case of breakage.

A still further object of my invention is to provide an improved aeroplane propeller of the above character, which will be durable and eliicient in use, one that will be simple and easy to manufacture, and one which can A bevplaced upon themarket at a reasonable cost.

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated inthe accompanying drawing, in which drawing `and outersections 10 and 11.

line 2--2 offldligure llooking in the direction 55 of the arrows.

Figure 3 is a detail longitudinal section taken on the line SW3 of Figure'l, looking in` the direction of the arrows. 7 i

Figure 4: is a diametric section taken on the 60 line les of Figure 1 looking in the direction of the arrows.

`Figure 5 is a detail perspective View of the sectional cup for bracing the propeller shaft and holding a set of blades in position.

Figure 6 is a front elevation of the spiral tip forthe propeller shaft.

. Referring to the drawing in detail, wherein f similar reference characters designate corresponding parts throughout the several Views, the letter A generally indicates my improved device, which comprises an`elongated proieller shaft S, embodying inner The section.l 10 maybe considered as a part of the engine 75 crank shaft,` and the facing ends of the sec tions l1O`and 11 are provided with reduced threaded extensions 12 and `13, respectively. rllhese shaft sections 10 and 1l are connected by a two part coupling 14, and the extensions SQ- 12 and "13 are threadediiito `the two parts of the couplingand held againstfrotation by theuse of suitable keys 15. The two parts of the coupling 14 canbesecured together by the use of suitablebolts 16 as shown.` At 85 opposite diametric points, the couplingll is provided with threadedsockets 17 for "a purpose which will be later described.`

` The propeller Vshaft S preferably tapers toi air rearward against the propeller blades which will now be described.

The propeller blades are arranged in sets along the propeller shaft S and I employ three or more sets of propeller blades, and in the drawing I have illustrated three sets of blades only, but it is to be understood that the numberof sets of blades can be increased. The first set of blades is indicated generally by the reference character 25, the second or intermediate set of blades by the reference character 35, and the third or inner set of blades by the reference character 45. inner or third set of blades 45 are of the greatest length and the inner ends of the blades are provided with reduced threaded extensions 46, which are threaded within the socket 17 of the two-part coupling member 14; If preferred, keys can be utilized for 20 holding these blades against accidental rotation.

By .the construction shown in Figures 8 and 4, it is obvious that the blades can be readily removed and replaced, in case the original blades become broken or cracked from any reason. As shown, the set of blades 45 embody two blades, which extend radially from the two part coupling 14, at diametrically opposite points, and these blades are shap-ed in accordance with my improved propeller blade design.

The first or leadingset of propeller blades likewise embodies two outwardly extending blades 26 arranged at diametrically opposite points, and the set of blades 35 also embodies two radially extending blades 36 arranged at diametrically opposite points relative tov one another. The sets of blades and 35 are connected to the propeller shaft section.

11 in the same manner and each of the means for connecting the blades in place includes a two part cup` 27 for embracing the propeller shaft. The longitudinal edges of the cup 27 are provided with flanges 28, which can be connected together by means of bolts 16. The sections of the cup 27 on opposite sides thereof are provided with internally threaded sockets 29 for the reception of the reduced threaded sections formed on the inner end of the blades of the sets of blades 25 and 35. If desired, these blades caribe keyed in place to prevent accidental rotation thereof. Likewise, after the two part cups are bolted around the shaft, keys 30' can be utilized for 'Y preventing rotary as well as longitudinal movement of the cup on the shaft.

The lengt-hs of the blades of the sets of blades gradually diminish from the rear set of blades to the front set of blades 25, and thus the length of the set of blades 35. are less than the length of the set of blades 45, while the length of the set of blades 25 is less than the length of the set of blades 35.

Each set of blades is arranged at a differentangle on the shaft from thek other sets of The blades, as clearly .shown in Figure 2, and these blades of the sets of blades are staggered relative to one another.

From the foregoing description, it can be .seen that I have proveded a novel propeller embodying a series of sets of blades arranged in stepped relation on` the propeller shaft, whereby the air is successively acted upon bythe sets of blades, and whereby the air is directed back on the blades by the spiral tip of the propeller shaft.

Changes in details may be made without departing from the spirit or the scope of this invention, but

What I claim as new is: l

In combination with a propeller shaft, of a spiral pointed tip connected to the leading end of said propeller shaft, the spiral of said4 tip extending from the very o uter extremity and apex to the rear end of' said Y tip, a series of separate sets of propeller` blades arranged in spaced relation Within. the lengthof the propeller shaft for producing a continuous spiral from the very apex of the tip to the outer end of the last set ofblades, each set extending at an angle to the remaining sets, the length of the blades of the various sets gradually increasing from the forward to the rear end of said propeller shaft, the outer ends of the various sets of' blades terminating on an angle line constituting a substantial continuation of the angle of the edges of the spiral pointed tip to provide an elongated tapering spiral pulling means due to the location, length and as sembly of the various blades, this spiral pulling means extending from the very apex of said spiral pointed tip to the outer ends of the last set ofblades carried by the said propeller shaft.

f In testimony whereof I affix my signature.

STEVEN FTAGEK. 

